JPH10303270A - Carrying method of wafer cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carrying method of a wafer cassette wherein carrying trouble in loading/unloading a wafer cassette in process installation is prevented. SOLUTION: A carrying method contains the following; a step S40 wherein whether or not preparation of the state capable of loading/unloading a wafer cassette in process installation is finished is checked in the course of photo- coupled parallel I/O communication, a step S30 wherein the state capable of loading/unloading the wafer cassette in process installation is prepared when the state capable of loading/unloading the wafer cassette is not prepared, and a step S50 wherein the loading/unloading work of the wafer cassette is performed between an AGV(automatic guide vehicle) and process equipment when the preparation of the state capable of loading/unloading the wafer cassette is finished.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a wafer cassette (Wa).
fer cassette), more specifically, loading / unloading of wafer cassettes (Loadin).
AGV (Automated Guided Veh) for g / Unloading
icle: automatic guided vehicle) and the process equipment during the photocoupled parallel I / O transmission, check whether the loading / unloading of the wafer cassette of the process equipment is ready or not, and then check with the AGV. The present invention relates to a wafer cassette transfer method for loading / unloading a wafer cassette between process equipment and preventing a wafer cassette transfer accident.

[0002]

2. Description of the Related Art As is well known, in the early stage of automation of a semiconductor manufacturing line (Line), mainly processing operations of process equipment and measurement equipment itself were automated. Since the transfer of the wafer cassette was hardly automated, the transfer of the wafer cassette between the equipments was performed by an operator.

[0003] In recent years, as the ultra-high integration of semiconductor devices has progressed, particles generated from the human body of workers have become a major source of contamination of semiconductor devices. Accordingly, automation of a transfer system for transferring a wafer cassette has been intensively researched and developed, and has now reached a very high level.

FIG. 6 is a schematic diagram showing a configuration of a wafer cassette transfer system using a general photocoupled parallel I / O communication, and FIG. 7 is a loading / unloading unit of the process equipment shown in FIG. FIG. 7 is a layout view showing a state where a sensor is arranged on the cassette stage of FIG.

As shown in the figure, in a wafer cassette transfer system, a controller 11 of a transfer equipment 10 and a controller (not shown) of a process equipment 20 have an SECS (Semiconductor Equipment Community).
ication Standard) Host computer for communication (Host)
Computer 30 is controlled by the transport equipment 10
AGV 13 is controlled by the controller 11 by wireless communication, and the AGV 13 is photo-coupled with the process equipment 20 in parallel I / O communication (Photo-copled Parallel Input / O
It is configured to transfer a wafer cassette (not shown) while performing utput communication. Also, a sensor that detects whether the wafer cassette is in the correct position (Sensor)
S1 is located on the surface of a cassette stage 21 in the loading / unloading section of the process equipment 20.

A conventional wafer cassette transfer method using the wafer cassette transfer system configured as described above will be described as follows. First, the controller 11 of the transfer equipment 10 and the controller (not shown) of the process equipment 20 are respectively connected to the host computer 30 and the SE for loading / unloading the wafer cassette.
When the CS communication is performed, the controller 11 controls the AGV 13 to move in front of the process equipment 20 for loading / unloading the wafer cassette through wireless communication, so that the AGV 13 moves and arrives in front of the process equipment 20.

Thereafter, the AGV 13 starts parallel I / O communication that is photocoupled with the process equipment 20 to start the process equipment 20.
Prepares an internal mechanical device (not shown) in a state where loading / unloading of a wafer cassette is possible.
Parallel I where GV13 is photocoupled to process equipment 20
The loading / unloading of the wafer cassette is performed while continuing the / O communication. Here, the photo-coupled I / O communication is performed between the AGV 13 and the process equipment 20.
SEMI (Semico) to transfer wafer cassettes between
nductor Equipment & Material International).

[0008]

However, the number of process equipment is two.
0, for example, the loading / unloading possible state of the internal mechanical device, for example, the loading / unloading possible state is prepared so that the door of the loading / unloading part of the wafer cassette is opened and the robot arm (Robot Arm) is extended. Despite the necessity of completion, the door may not be opened due to various factors, the robot arm may not be extended, or the wafer cassette may not be accurately positioned on the cassette stage. In some cases, the ready state of loading / unloading was not completed.

For example, as shown in FIG. 7, an operator does not accurately position a wafer cassette (not shown) at a point a of a cassette stage 21 in a loading section, and a wafer cassette is placed at a point next to the point a. Is positioned, the wafer cassette detection sensor only detects the wafer cassette (not shown) positioned at the normal position, so that the cassette stage 2
It is erroneously sensed that the wafer cassette does not exist in 1. Further, conventionally, it was not possible to check at all whether such a case occurred before loading / unloading the wafer cassette.

Further, the AGV 13 performs loading / unloading of the wafer cassette under the above-described conditions, so that another wafer cassette is stacked on the wafer cassette positioned on the cassette stage 21 or the AGV 13 is loaded. In some cases, a transfer accident such as a collision of a loaded wafer cassette with a door of the process equipment 20 that has not been opened or a drop of the wafer cassette from the vacant space occurs.

Therefore, an object of the present invention is to interrupt the loading / unloading of the wafer cassette between the AGV and the process equipment when the possible state of the loading / unloading of the wafer cassette of the process equipment is not completed. It is an object of the present invention to provide a method of transporting a wafer cassette which prevents a wafer cassette from being transported.

[0012]

According to the present invention, there is provided a method for transporting a wafer cassette, which comprises the steps of: checking whether a loading / unloading state of a process-equipped wafer cassette is ready; When it is checked that the loading / unloading state of the cassette is ready, the loading / unloading of the wafer cassette between the AVG and the process equipment is performed, and the loading / unloading state of the wafer cassette is ready. When it is checked that the wafer cassette has not been loaded, the loading / unloading of the wafer cassette is shut off. Therefore, the present invention can prevent a loading / unloading accident of the wafer cassette which occurs when the ready state of the loading / unloading of the process equipment is not completed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for transferring a wafer cassette according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic diagram showing a configuration of a wafer cassette transfer system using photocoupled parallel I / O communication applied to a wafer cassette transfer method according to the present invention, and FIG. FIG. 5 is an arrangement diagram illustrating a state where a sensor is arranged on a cassette stage of a loading unit / unloading unit.

As shown in the drawing, the wafer cassette transfer system of the present invention is different from the process equipment 20 shown in FIG. 7 except that sensors S2 and S3 are additionally installed on the cassette stage 41 of the process equipment 40. It has the same structure. Here, the sensor S1 for detecting whether the wafer cassette is present at the normal position is located on the surface of the cassette stage 41 in the loading / unloading section of the process equipment 40, and the wafer is located at a position other than the normal position of the cassette stage 41. Sensors S2 and S3 for detecting whether a cassette is present are located adjacent to the cassette stage 41.

A method of transporting a wafer cassette using the wafer cassette transport system configured as described above will be described with reference to FIGS. FIG. 3 is a flowchart showing a method of transferring a wafer cassette according to the present invention. FIG. 4 is a timing chart showing loading of a wafer cassette applied to the method of transferring a wafer cassette according to the present invention. FIG. 9 is a timing chart showing unloading of a wafer cassette applied to the cassette transfer method.

As shown in FIG. 3, the method of transporting a wafer cassette according to the present invention includes a step S10 in which the AGV 13 of the transport equipment 10 starts photo-coupled parallel I / O communication with the process equipment 40 in a wireless communication system. The AGV 13 after the photocoupled parallel I / O communication is started.
A step S20 of designating a cassette stage (not shown) of the process equipment 40, a step S30 of preparing a loading / unloading possible state of the wafer cassette of the designated process equipment 40, and a step S30 of loading / unloading the wafer cassette. Step S40 of checking whether the preparation of the unloading possible state is completed, and loading / unloading of the wafer cassette between the AGV 13 and the process equipment 40 when it is checked that the loading / unloading possible state is completed. Performing S50, releasing the cassette stage number designation when the loading / unloading of the wafer cassette is completed, and performing the parallel I / O communication when the cassette stage number designation is released. Performed at the end step S70 That.

Referring now to FIG. 4, a method of transferring a wafer cassette according to the present invention will be described focusing on the loading of the wafer cassette. First, when the controller 11 of the transfer equipment 10 and the controller (not shown) of the process equipment 40 perform SESC communication for loading the wafer cassette with the host computer 30, respectively, the controller 11 executes the AGV1 loading the wafer cassette.
By controlling the AGV 13 to move in front of the process equipment 40 for loading the wafer cassette through wireless communication with the device 3, the AGV 13 starts moving in front of the process equipment 40.

Next, in step S10, after the AGV 13 arrives, the parallel I / O photo-coupled with the process equipment 40 is performed.
When the communication starts, the AGV 13 designates a cassette stage (not shown) of the process equipment 40 in step S20.

That is, a high-level signal (CS_NO ON) indicating the cassette stage for which the AGV 13 is designated is transmitted to the process equipment 40, and a high-level signal indicating that the signal (CS_NO ON) is valid. By starting transmission of (VALID ON) to the process equipment 40, the cassette stage number is designated. Here, CS_NO is the cassette stage number, for example, CS_0, CS_1, CS_
Means 2 etc.

Next, in step S30, the process equipment 40 prepares an internal mechanical device (not shown) so that the wafer cassette can be loaded. More specifically, if there is a door of the loading unit of the process equipment 40, the door is opened, and if there is a robot arm, the robot arm can be extended. Further, a sensor (not shown) of the process equipment 40 checks whether the wafer cassette is positioned on the cassette stage of the loading section. At this time, step S30
Does not matter if the AGV 13 is carried out before reaching the process equipment 40.

In step S40, a sensor of the process equipment 40 senses whether the door is opened or closed, whether the robot arm is extended, the presence or absence of the wafer cassette on the cassette stage, and the like. provide. The controller checks, based on this, whether the wafer cassette is ready for loading.

At this time, if it is checked that the ready state of the loading of the wafer cassette of the process equipment 40 has not been completed, the loading of the wafer cassette is not performed, and the step 30 is performed again. That is, although it is necessary to open the door and extend the robot arm to prepare for a loadable state where no wafer cassette is present on the cassette stage, the door is actually opened due to various factors. In some cases, the robot arm is not released, the robot arm is not extended, and the wafer cassette is not accurately positioned on the cassette stage, and the ready state for loading is not completed.

For example, as shown in FIG. 2, the operator does not accurately position the wafer cassette (not shown) at the point a of the cassette stage 41 of the loading section.
When the wafer cassette is positioned at a point next to
1 detects only the wafer cassette (not shown) positioned at the normal position, and thus erroneously senses that there is no wafer cassette on the cassette stage 41.

Therefore, in the present invention for complementing this, by additionally providing the optical sensors S2 and S3,
It is sensed that a wafer cassette located at a position other than the normal position of the cassette stage 41 also exists on the cassette stage 41.

As described above, under the condition that any one of the sensors S1, S2, and S3 detects that the wafer cassette is present, the process equipment 40 checks that the wafer cassette is not ready to be loaded with the wafer cassette. , Does not transmit a high state signal (L_REQ ON) indicating the cassette stage loading enabled state to the AGV 13.

Therefore, since the AGV 13 does not perform the loading of the wafer cassette, the wafer cassette is stacked on the wafer cassette located on the cassette stage, or the wafer cassette loaded by the AGV 13 is attached to the door of the process equipment 40 which is not opened. Transport accidents such as collision or dropping of the wafer cassette from the vacant space do not occur.

On the other hand, if it is checked that the loading state of the wafer cassette is ready, for example, the wafer cassette is not located on the cassette stage, and all of the sensors S1, S2 and S3 detect that the wafer cassette is not present. Then, step S50 is performed. That is,
The process equipment 40 starts transmitting a signal (L_REQ ON) indicating that the cassette stage can be loaded to the AGV 13.

As a result, the transmission of a high state signal (TR_REQ ON) indicating that the AGV 13 intends to convey to the process equipment 40 is started. At this time, if the cassette stage is ready for loading, the process equipment 4
0 starts transmitting a signal (READYON) in a high state to the AGV 13. Here, it does not matter if the check period of step S40 is extended before transmission of the signal (READY ON).

Thereafter, the AGV 13 starts loading the wafer cassette onto a cassette stage (not shown) of the process equipment 40 and starts transmitting a high state signal (BUSY ON) to the process equipment 40.

After the wafer cassette has been loaded, the presence of the wafer cassette on the cassette stage is checked by a sensor. At this time, the process equipment 40 changes the high state signal (L_REQ ON) to the low state signal (L_REQ) to indicate that the wafer cassette is present.
OFF) and transmits to AGV13.

Next, the AGV 13 outputs a high state signal (BUSY
ON) is converted to a low state signal (BUSY OFF) and transmitted to the process equipment 40, and a high state signal (COMP ON) indicating completion of loading is transmitted to the process equipment 40.

Thereafter, in step S60, the process equipment 40 changes the high state signal (READY ON) to the low state signal (READY OF).
F), and transmits the signal to the AGV 13, and then the signal of the high state (BUSY ON) of the AGV 13 is changed to the signal (BUSY OF) of the low state.
F) and sends it to the process equipment 40, and also changes the high state signal (VALID ON) to the low state signal (VALID OFF).
Then, the high state signal (CS_NO ON) is converted to a low state signal (CS_NO OFF) and transmitted to the process equipment 40.
Therefore, the designation of the cassette stage number is released.

After the designation of the cassette stage number is released, in step S70, the parallel I / O communication in which the AGV 13 is photocoupled to the process equipment 40 is completed. Since then
If the continuous loading / unloading operation is not performed, the AGV 13 is isolated from the process equipment 40.

Referring to FIG. 5, a method of transferring a wafer cassette according to the present invention will be described focusing on unloading of the wafer cassette. First, when the controller 11 of the transport equipment 10 and the controller (not shown) of the process equipment 40 perform SESC communication for unloading the wafer cassette with the host computer 30, respectively, the controller 11 executes the AGV 13 loaded with the wafer cassette. The AGV 13 starts moving in front of the process equipment 40 by controlling the AGV 13 to move in front of the process equipment 40 for unloading the wafer cassette through wireless communication with the device.

Next, in step S10, after the AGV 13 arrives, the parallel I / O photo-coupled to the process equipment 40 is performed.
Start communication. In step S20, the AGV 13 specifies a cassette stage (not shown) of the process equipment 40.
That is, the AGV 13 starts transmitting a high state signal (CS_NO ON) indicating the designated cassette stage to the process equipment 40, and at the same time, a high state signal (VALID ON) indicating that the signal (CS_NO ON) is valid. Is transmitted to the process equipment 40, whereby the number of the cassette stage is designated. Here, CS_NO means a cassette stage number, for example, CS_0, CS_1, CS_2, and the like.

Next, in step S30, the process equipment 40 prepares an internal mechanical device (not shown) so that the wafer cassette can be unloaded. To explain this in more detail, the process equipment 40 opens the door of the unloading unit and extends the robot arm. Further, the sensor of the process equipment 40 checks whether the wafer cassette after the process is completed is positioned on the cassette stage 40 of the unloading unit. Here, it does not matter if step S30 is performed before the AGV 13 arrives in front of the process equipment 40.

In step S40, various sensors of the process equipment 40 detect whether the door is opened and closed, whether the robot arm is extended, the presence or absence of the wafer cassette on the cassette stage, and the like. To provide. The controller checks whether the wafer cassette is ready for unloading based on this.

At this time, if it is checked that the ready state of the unloading of the wafer cassette of the process equipment 40 has not been completed, the step 30 is repeated without unloading the wafer cassette. That is, despite the fact that it is necessary to open the door and extend the robot arm to prepare for the unloading ready state where the wafer cassette is present on the cassette stage, in practice, due to various factors, In some cases, the door is not opened, the robot arm is not extended, the wafer cassette is not accurately positioned on the cassette stage, and the ready state for unloading is not completed.

For example, as shown in FIG. 2, the operator moves the point a on the cassette stage 41 of the unloading section.
If the wafer cassette (not shown) is not accurately positioned and the wafer cassette is positioned at a point next to the point a, the sensor S1 senses only the wafer cassette (not shown) positioned at the normal position. It is erroneously sensed that the wafer cassette does not exist on the stage 41.

Therefore, in the present invention for complementing this, by additionally installing the optical sensors S2 and S3, the wafer cassettes located at positions other than the normal position of the cassette stage 41 are also provided on the cassette stage 41. Perceived to be present.

As described above, under the condition that all the sensors S1, S2, and S3 detect that the wafer cassette does not exist, the process equipment 40 checks that the unloadable state of the wafer cassette has not been completed. A high state signal (U_REQ ON) indicating the unloading enabled state is not transmitted to the AGV 13. Therefore, since the AGV 13 does not perform the wafer cassette unloading, the transfer accident of the wafer cassette does not occur.

On the other hand, when it is checked that the unloadable state of the wafer cassette of the process equipment 40 is ready, for example, the wafer cassette is positioned at the correct position of the cassette stage and all the sensors S1, S2, S3 are set. If it is detected that a wafer cassette is present, step S50 is performed.
Is performed. More specifically, when it is checked that the unloadable state of the wafer cassette is ready, the process equipment 40 outputs a high state signal (U_RE) indicating the unloadable state of the cassette stage.
Q ON) to the AGV 13 is started.

As a result, the high-level signal (TR_REQ ON) indicating that the AGV 13 is about to convey is started to be transmitted to the process equipment 40. At this time, if the cassette stage is ready to be ready for unloading, the process equipment 40 starts transmitting a high state signal (READY ON) to the AGV 13. Here, it does not matter if the check period of step S40 is extended before transmission of the signal (READY ON).

Thereafter, the AGV 13 starts unloading of the wafer cassette to a cassette stage (not shown) of the process equipment 40, and at the same time, outputs a high state signal (BUSY O).
N) to the process equipment 40 is started.

After the wafer cassette is unloaded, it is checked by a sensor that no wafer cassette exists on the cassette stage. At this time, the process equipment 40 converts the high state signal (U_REQ ON) to a low state signal (U_REQ OFF) and transmits the signal to the AGV 13 to indicate that there is no wafer cassette.

Next, the AGV 13 outputs a high state signal (BUSY
ON) is converted to a low state signal (BUSY OFF) and transmitted to the process equipment 40, and a high state signal (COMP ON) indicating completion of unloading is transmitted to the process equipment 40.

Thereafter, in step S60, the process equipment 40 changes the high state signal (READY ON) to the low state signal (READY OF).
F) and transmits the signal to the AGV 13, after which the signal of the high state (BUSY ON) of the AGV 13 is changed to the signal of the low state (BUSY OF)
F) and sends it to the process equipment 40, and also changes the high state signal (VALID ON) to the low state signal (VALID OFF).
Then, the high state signal (CS_NO ON) is converted to a low state signal (CS_NO OFF) and transmitted to the process equipment 40.
Therefore, the designation of the cassette stage number is released.

In step S70, when the designation of the cassette stage number is released, the parallel I / O communication in which the AGV 13 is photocoupled to the process equipment 40 is terminated. Since then
If the loading / unloading operation is not performed continuously, the AGV 13 is separated from the process equipment 40.

Although the preferred embodiment of the present invention has been described in detail, those skilled in the art to which the present invention pertains have the spirit and scope of the present invention defined in the appended claims. The present invention can be variously modified or changed without departing from the scope of the present invention.

[0050]

As described above, in the wafer cassette transfer method according to the present invention, the presence / absence of preparation for the loading / unloading state of the wafer cassette equipped with the process equipment is checked to determine whether the loading / unloading state of the wafer cassette is possible. The AGV performs loading / unloading of the wafer cassette only when the preparation is completed. Therefore, the present invention prevents the AGV from performing the loading / unloading of the wafer cassette when the loading / unloading available state of the process equipment is not completed, thereby loading / unloading the wafer cassette. Accidents are prevented.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a wafer cassette transfer system using photocoupled parallel I / O communication applied to a wafer cassette transfer method according to the present invention.

FIG. 2 is a layout diagram showing a state where a sensor is arranged on a cassette stage of a loading unit / unloading unit of the process equipment of FIG. 1;

FIG. 3 is a flowchart illustrating a wafer cassette transfer method according to the present invention.

FIG. 4 is a timing chart showing loading of the wafer cassette applied to the wafer cassette transfer method according to the present invention.

FIG. 5 is a timing diagram illustrating unloading of a wafer cassette applied to the wafer cassette transfer method according to the present invention.

FIG. 6 is a schematic diagram showing a configuration of a conventional wafer cassette transfer system using photocoupled parallel I / O communication.

7 is an arrangement view showing a state where a sensor is arranged on a cassette stage of a loading unit / unloading unit of the process equipment of FIG. 6;

[Explanation of symbols]

 Reference Signs List 10 transport equipment 11 controller 13 AGV 20, 40 process equipment 21, 41 cassette stage 30 host computer S1, S2, S3 sensor

Claims (4)

[Claims] 1. A wafer cassette between an AGV having a transfer device for loading / unloading a wafer cassette using photocoupled parallel I / O communication and a process device for loading / unloading the wafer cassette. Loading / unloading the photocoupled parallel I / O communication while the
Checking whether the loading / unloading state of the wafer cassette of the process equipment is ready; and if the loading / unloading state of the wafer cassette is not ready, loading / cutting the wafer cut of the process equipment. Preparing an unloadable state; and performing a loading / unloading operation of the wafer cassette between the AGV and the process equipment when the loading / unloading possible state of the wafer cassette is completed. A method for transporting a wafer cassette, comprising: 2. The step of checking whether the wafer cassette is ready for loading / unloading is performed by sending a signal indicating that the process equipment is in a high state to the AGV.
2. The method according to claim 1, wherein the method is carried out before the transmission to the wafer cassette. 3. The step of checking whether or not the preparation is completed includes detecting whether a wafer cassette is present at a correct position on the cassette stage using a sensor of a loading / unloading unit of the process equipment. 2. The apparatus according to claim 1, wherein a sensor of the loading / unloading unit is used to detect whether the wafer cassette is present at a position other than the normal position of the cassette stage.
3. The method according to claim 2, wherein the wafer cassette is transported. 4. The method according to claim 3, wherein the sensor is located adjacent to the cassette stage.